A new helical model of bacterial cell surface organization and growth has recently been proposed by our group. This model was deduced from the analysis of a complex multiple-mutant of Bacillus subtilis that grows in a double-helix morphology. During the forthcoming year we propose to test the generality of helix cell surface organization by searching for rotation of cell poles as the cylindrical regions of the cell elongate during growth. We also plan to study DNA segregation in growing cells in view of numerous published figures of nucleoids which suggest that a helical path may also be followed. This might be expected if DNA segregation is facilitated by attachment of DNA to the cell surface, and the surface is organized with respect to expansion in a helical configuration. The helical cell system also provides an opportunity to study cell-cell interactions and quasi-developmental phenomena in a bacterial system. Related aspects of our newly described zebra-system will also be investigated. Our objectives remain to gain further knowledge concerning regulation of growth and division in bacterial cells. BIBLIOGRAPHIC REFERENCES: Mendelson, N.H. 1976. Helical cell organization and growth in Bacillus subtilis. Abst. Ann. Mtg. of the Amer. Soc. for Microbiol. I 99 P. 128 (Abstract). Mendelson, N.H. 1976. Helical growth of Bacillus subtilis: A New model of cell growth. Proc. Nat. Acad. Sci. U.S.A. 73:1740-1744.